Every holiday gathering has a grinch. You know their M.O.: They take a certain tone of voice. Dish out a thinly veiled criticism. Pose a nosy question. If there's one thing you can count on for Christmas, it's that moment when a seasonal saboteur—and every family has at least one—broaches a topic that rubs you the wrong way.

Sad but true, people who share your history tend to know your vulnerabilities—which means they also have the emotional intel needed to trigger them. At the same time, if you want to avoid feeling like a wet stocking is snuffing out your holiday spirit, it's important to recognize that sometimes harm was intended (consciously or not).

So what can you do if (OK, let's face it—they will) the touchy topics come up? Try these tips from human behavior and etiquette experts to come through with grace and humor.

Touchy topic: Your love life...They say: "Have you ever tried online dating?"You hear: "Wow. You're still single?"How to handle it: If you get this question every holiday, then make like a girl scout and be prepared, for heaven's sake. Jodi R. R. Smith, president of Mannersmith, an etiquette consulting firm, calls this preemptive etiquette. "If you're single, it's 'Are you dating someone,' and if you're dating, it's 'When are you getting married,' and then, 'When are you having children?' " says Smith. Have a response ready for the predictable questions, says Wendy Walsh, PhD, a relationships and human behavior expert. In this case, go with humor: "Online?! I get hit on every time I walk down the street! It's exhausting, really." Another option? "Nope, the full-page newspaper ad is working just fine."

Touchy topic: Your priorities...They say: "When was the last time you were home?"You hear: "You don't come home nearly enough."How to handle it: "When faced with a guilt tripper, keep your answer simple, and positive," says Michelle Skeen, PsyD, author of The Critical Partner. "The more details you go into defending yourself, the more the person knows they've gotten under your skin." Just say: "Not as often as I'd like." No one can argue with that response—which is exactly the point. "The idea is to deflect the snarky remark rather than escalate a negative encounter," Skeen adds.

Touchy topic: Your weight...They say: "Do you want a whole leftover turkey sandwich, or a half?"You hear: "You've gotten fat."How to handle it: "We don't always know how a person intended a question," says Walsh. "A lot can be about what's going on inside you." In other words, be careful not to jump to conclusions and project any food guilt you might be feeling. Instead, deal concretely with exactly what you hear, Walsh advises. Try, "Your turkey is so delicious, I would love a whole." If the words were innocent, you're not guilty of starting a war. If you were under attack? Well, look at you, rising above it. "If you're happy with yourself, you'll drive the critics nuts," she says.

They say: "Well, look at you, all decked out for the holidays."You hear: "Did you get dressed in the dark?"How to handle it: Let kindness be your best defense. "It feels good, plus nothing shuts a critic down more than when you ignore whatever you think is the underlying criticism," says Skeen. "In this case, say, 'Thank you. It's fun to add some cheer with some holiday gear.' " Above all, try compassion, she advises. "Remember that at their core, critics feel flawed or defective, or they wouldn't be criticizing you."

Touchy topic: Your kids...They say: "Your kids are so…energetic."You hear: "Your kids are completely out of control."How to handle it: Here's how to get the Family Judge off your case for good. "With each comment, acknowledge the remark, deflect it—and give this critic an assignment," says Smith. For example, try: "Yes, they're so happy and energetic—I'm actually basting the turkey at the moment, so it would be fabulous if you'd take them outside for about 20 minutes." You'll soon condition her to stop her snippy comments because she doesn't want to help, says Smith.

Touchy topic: Your cooking...They say: "What's in this?"You hear: "I hate your food."How to handle it: "If the tone tells you this is a bullying comment, then I suggest going into Faux Emergency Mode," says Smith. "Say, 'Oh my god, do you have an allergy—what are you allergic to?!' If they say, 'No, I don't have allergies,' say, 'Oh, good,' and move on to another topic." If the question came from a genuine health concern, then you've responded appropriately; and if it was meant to hurt you, then it's pretty clear who won that battle.

Touchy topic: Your hair...

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They say: "You look so...different."You hear: "OMG, what have you done to your hair?"How to handle it: Anyone who's ever gotten a bad haircut doesn't need it pointed out—you're aware that your new pixie makes you look like a lollipop, thank you very much. "Some social remarks are simply dimwitted," says Smith. But remember that someone out to zap you would come up with something that has more bite. Her advice: "Have some fun with this. Ask bizarre questions like 'Do you think it's my L.L. Bean boots?' When they finally catch up and realize you have a really lousy haircut, they'll probably want to drop it." At that point, let them off the hook and ask what's new with them. (Make things easier on yourself with these 6 fast ways to fake fabulous hair.)

Touchy topic: Your home...They say: "I just found a great new cleaning service. Do you want their number?"You hear: "Your home is a pigsty. Shame on you."How to handle it: "I hear empathy here, not judgment," says Smith. "Houses that are lived in get dirty—that's just the way it is. So I see this as somebody who's excited she's found a solution, one of those people with a helpful personality." Instead of taking it personally, simply say "yes." If you feel snarkiness oozing out of every syllable, you can still field the question gracefully. Walsh suggests: "Simply say, 'Thanks,' take the number, and change the subject."

Touchy topic: Your past...

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They say: "Remember when you got plastered at Becky's wedding?"You hear: "I enjoy embarrassing you at every given opportunity."How to handle it: "This is someone who feels better about himself if he makes other people feel worse," says Smith. "Every family has a person like this." The solution? Take ownership of whatever embarrassing story they were about to tell, and beat them to the punch line, Smith advises. Instead of getting defensive, Skeen suggests saying something like, "I remember having a great time at the wedding. And a great big hangover the next day." Score one for you for deflating a bully.

Touch topic: Your parenting skills...They say: "So your son's living at home again?"You hear: "Wow, did you screw up your kid!"How to handle it: If you expect this comment, Walsh says, "Be ready to broaden the discussion. Say, 'Can you believe our family's part of a whole trend in our culture? So many young people can't find work and are living at home.' " You'll transform it into a macro sociological discussion for the whole table, she says. Nicely done. You're on a roll.